Is possible use client object model (C#/JavaScript) or web service to approve SharePoint customer workflow? If update task item directly, the workflow seem like cannot move to next step. Has any approach to handle it?
Also, when I start list workflow in SharePoint apps, it will assign to someone to approve task. BTW, when the user visit my-site and click the task, it will flow 403 error like no permission. I think this is related apps cannot access application page in _layout. I use Office 365 online SharePoint.
Thanks.